Super-soldiers like the Astartes actually had fairly ordinary armor and firepower within humanity's armed systems.
The Astartes had Boltguns, and the Astra Militarum had comparable weapons too. No matter how tough Astartes armor was, could it be tougher than a Leman Russ tank?
What truly made the Astartes exceptional was their superhuman reaction speed.
With the superhuman neural systems that granted them such incredible reflexes, if they played CS, even five donks couldn't beat an Astartes. The moment they met, they'd be one-tapped!
Backed by those superhuman reflexes, equipped with Power Armor that was basically immune to small-arms fire and had a chance of resisting heavy weapons, plus suitably powerful Boltguns, they became battlefield reapers capable of facing a thousand enemies alone!
As for ordinary humans, increasing their neural reaction speed enough to contend with the Astartes was basically impossible. They wouldn't catch up even in a thousand years.
Since that was the case, Li Qinwu decided to sacrifice some of the Power Armor's mobility and stack its performance toward defense.
At the very least, the front of the Power Armor had to be able to withstand Astartes Boltgun fire.
If Li Qinwu's troops ever truly came under attack from the Astartes in the future, the Astartes would definitely get the first shot!
Therefore, the Power Armor he built had to at least be capable of blocking Boltgun fire!
As for firepower, there were plenty of weapons that could penetrate Astartes Power Armor, such as other Boltguns, High-Power Lasguns, Meltaguns, Ion Guns, and so on.
In short, his infantry had to survive first. Only then would they have room to perform.
With those requirements in mind, Li Qinwu went back to revising his design in the drafting software.
There was no way Power Armor designed by an amateur like Li